llvm-6502/test/Transforms/LoopRotate/simplifylatch.ll
Andrew Trick f6629ab847 Add simplifyLoopLatch to LoopRotate pass.
This folds a simple loop tail into a loop latch. It covers the common (in fortran) case of postincrement loops. It's a "free" way to expose this type of loop to downstream loop optimizations that bail out on non-canonical loops (getLoopLatch is a heavily used check).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@150439 91177308-0d34-0410-b5e6-96231b3b80d8
2012-02-14 00:00:23 +00:00

40 lines
1021 B
LLVM

; RUN: opt -S < %s -loop-rotate -verify-dom-info -verify-loop-info | FileCheck %s
; PR2624 unroll multiple exits
@mode_table = global [4 x i32] zeroinitializer ; <[4 x i32]*> [#uses=1]
; CHECK: @f
; CHECK-NOT: bb4
define i8 @f() {
entry:
tail call i32 @fegetround( ) ; <i32>:0 [#uses=1]
br label %bb
bb: ; preds = %bb4, %entry
%mode.0 = phi i8 [ 0, %entry ], [ %indvar.next, %bb4 ] ; <i8> [#uses=4]
zext i8 %mode.0 to i32 ; <i32>:1 [#uses=1]
getelementptr [4 x i32]* @mode_table, i32 0, i32 %1 ; <i32*>:2 [#uses=1]
load i32* %2, align 4 ; <i32>:3 [#uses=1]
icmp eq i32 %3, %0 ; <i1>:4 [#uses=1]
br i1 %4, label %bb1, label %bb2
bb1: ; preds = %bb
ret i8 %mode.0
bb2: ; preds = %bb
icmp eq i8 %mode.0, 1 ; <i1>:5 [#uses=1]
br i1 %5, label %bb5, label %bb4
bb4: ; preds = %bb2
%indvar.next = add i8 %mode.0, 1 ; <i8> [#uses=1]
br label %bb
bb5: ; preds = %bb2
tail call void @raise_exception( ) noreturn
unreachable
}
declare i32 @fegetround()
declare void @raise_exception() noreturn